1. Field of the Invention
The present invention relates to image processing on a document including different types of images.
2. Description of Prior Art
A document may include different types of images such as characters, line images, pictures and characters not recognized. It is known to process different types of images separately and to compose them to integrate a document image. For example, bit map images are generated from character codes, from characters not recognized and from non-character images and they are composed (Japanese patent laid open publication 9-91371/1997). In another way, in order to use rounded characters, character images are modified without using font of the rounded characters, and they are composed with the other image (Japanese patent laid open publication 5-134651/1993). In a different way, when an image data is converted to another image data of a different format, regions of characters, line images and pictures are converted in different forms at the same time, and the image is reconstructed (Japanese patent laid open publication 5-20495/1993).
In an image processing system, different types of regions are separated from bit map data obtained by scanning a document. Character regions are converted to code data with optical character recognition, line image regions are converted to vector data, and the other regions are processed as bit map data. Then, these data are composed and the resultant integrated image is outputted. However, the images may not be composed fitly in the integrated image. For example, when vector data are generated, the precision of the position of the edited image may not be correct sufficiently. Therefore, when vector data are composed with the original image, the original image is superposed around the vector data, so that a blurred image may be outputted. For example, in an image wherein colors are different at both sides of a straight line, the image around the straight line may be blurred, or in an image including a bit map image enclosed with vector data, the boundary thereof may be blurred.